LOANS HELD FOR INVESTMENT, Age Analysis on Accruing Past-due Loans and Nonaccrual Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	$ 3,011,799	$ 3,014,153
Total Nonaccrual	2,012	3,242
Nonaccrual with no ACL	579	580
30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	4,274	6,230
90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	1,368	1,935
Commercial Real Estate [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	1,110,283	1,081,056
Total Nonaccrual	0	0
Nonaccrual with no ACL	0	0
Commercial Real Estate [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	363	499
Commercial Real Estate [Member] | 90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	16	86
Commercial [Member] | Specialized [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	351,546	372,376
Total Nonaccrual	698	213
Nonaccrual with no ACL	521	0
Commercial [Member] | Specialized [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	284	521
Commercial [Member] | Specialized [Member] | 90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	0	0
Commercial [Member] | General [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	527,576	517,361
Total Nonaccrual	474	953
Nonaccrual with no ACL	58	0
Commercial [Member] | General [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	615	1,316
Commercial [Member] | General [Member] | 90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	266	296
Consumer [Member] | 1-4 Family Residential [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	545,116	534,731
Total Nonaccrual	812	1,828
Nonaccrual with no ACL	0	362
Consumer [Member] | 1-4 Family Residential [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	1,502	793
Consumer [Member] | 1-4 Family Residential [Member] | 90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	821	1,390
Consumer [Member] | Auto Loans [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	292,389	305,271
Total Nonaccrual	0	0
Nonaccrual with no ACL	0	0
Consumer [Member] | Auto Loans [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	692	1,208
Consumer [Member] | Auto Loans [Member] | 90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	136	60
Consumer [Member] | Other Consumer [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	71,698	74,168
Total Nonaccrual	28	30
Nonaccrual with no ACL	0	0
Consumer [Member] | Other Consumer [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	722	1,134
Consumer [Member] | Other Consumer [Member] | 90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	129	103
Construction [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	113,191	129,190
Total Nonaccrual	0	218
Nonaccrual with no ACL	0	218
Construction [Member] | 30-89 Days Past Due [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	96	759
Construction [Member] | 90 Days or More Past Due and Still Accruing [Member]
Age Analysis on Accruing Past-due Loans and Nonaccrual Loans [Abstract]
Past Due	$ 0	$ 0